I have a lot of native wildflowers in my yard. I let the seeds ripen on the plant and they all pretty much self sow.
They can and do look ratty and brown, but once I'm sure the seeds have ripened and scattered, I pull them out.
It usually doesn't all look bad at the same time, but they go in succession.

All of them do come back reliably the following spring.

wanda

You have to grit your teeth and let them stay long enough to drop mature seed on the ground before you pull them out. By then they look pretty awful. You also have to leave the area unmulched so the seed can reach the ground, lay there all summer, then sprout in place next fall. I usually plant some other kind of summer annual in the bare spot for the summer, it doesn't seem to be a problem. I have a large patch of Limnanthes douglasii that I just pulled up, and plan to put Melampodium paludosum there in the next few days.

As a compromise, you can choose to leave a few plants (at least 2 or 3) until the seeds ripen. Even one plant can produce a lot of seeds, but the more plants you can leave, the better genetic diversity you'll get. Think about it as a birdseed garden.

I have calif. poppies and globe gilia and a few clarkias. I pull up the poppies when I need the garden space to put something else in, because I know there are enough seeds in the soil already. I mulch my garden, and the tiny globe gilia seeds reseed themselves prolifically anyway. I collect a huge amount of seeds each year, let the birds have as many as they want, and pull out the globe gilia plants when they're crowding other plants, and they're slowly taking over and spreading from one corner of the garden. I've found I can replant the pulled-up plants easily, and I've given away a lot of plants. They're in bloom much of the year because I water other plants in that part of the garden.

The clarkias are not as prolific, but they come up in the garlic patch and I disturb the soil a lot in that part of the garden, adding compost and mulch throughout the year, so it's surprising they manage to come up at all! I pull up the garlic as I need it, and by the time the clarkias are big enough to bloom, I will have harvested most of the garlic. Most years I think about saving some seed, but I'm busy in other parts of the garden by the time the clarkia seeds drop, so I haven't saved any yet.

I also have some of the delicate ground-hugging Clarkia davyi, which reseeded itself in a few containers from the one plant I had last year, so I'm planning to move some of the containers to another part of the garden when they start going to seed.

By the way, that's the easiest way I know to grow wildflowers: put a container of the flowers in the spot where you want them to grow the next year, let them go to seed, and they'll reseed themselves there. I've found that I mostly give away any seeds I collect, since so many of these reseed themselves. I don't know if the phacelia tolerates transplanting, but if you were going to pull them out anyway, you could try transplanting a few to the area where you want a meadow and let them go to seed there. Just be sure to water them and keep an eye on them for a few days so they don't die before ripening the seed.

The most important thing about planting a meadow is to make sure the area is as weed-free as you can get it before starting, so that weeds won't outcompete the wildflowers. Or, if you've learned to recognize young wildflower seedlings, you can carefully weed out anything else while all the plants are small.

Great Help!

I actually would love to plant on a large slope I have, but it is very weedy. I did pull almost all the weeds this year and am headed out today to check it, as they should still come up easily from the last rain.
I like the idea of seeds for the birds too.
When is the best time to plant the wildflower seeds. Is it best to leave them uncovered?
The Desert Canterberry bells were beautiful... They are really blue and the leaves are burgundy tinged... They bloommed abundently. I have a newer one that just started blooming, although all the other bushes died off.
I really want to add a CA wildflower garden... will have to research ones that bloom at differant times.